import React, { useEffect, useState } from 'react'; function readHash() { const h = (window.location.hash || '').replace('#', ''); return h || 'home'; } export default function App() { const [route, setRoute] = useState(() => readHash()); useEffect(() => { function onHash() { setRoute(readHash()); } window.addEventListener('hashchange', onHash); onHash(); return () => window.removeEventListener('hashchange', onHash); }, []); return ( <div style={{ padding: 16 }}> <h2 style={{ marginTop: 0 }}>meetcode hash route</h2> <div style={{ display: 'flex', gap: 10 }}> <a href='#home'>Home</a> <a href='#topics'>Topics</a> <a href='#practice'>Practice</a> </div> <div style={{ marginTop: 10, color: '#555' }}>Active: {route}</div> </div> ); }